#
# This script was written by Noam Rathaus <noamr@securiteam.com>
#
# See the Nessus Scripts License for details
#

if(description)
{
 script_id(10175);
 script_version ("$Revision: 7518 $");
 script_tag(name:"risk_factor", value:"Medium");
 
 name = "Detect presence of PGPNet server and its version";
 script_name(name);
 
 desc = "
It is possible to detect the existing of PGPNet, by connecting to its
open UDP port (500) and sending it a session init packet, the PGPNet daemon
would respond (making it possible to know that PGPNet is installed on the
computer) with the version of the OpenPGP package it uses.

Solution: Block those ports from outside communication

Risk factor : Medium";

 script_description(desc);
 
 summary = "Detect presence of PGPNet server and its version";
 script_summary(summary);
 
 script_category(ACT_GATHER_INFO);
 
 script_copyright("This script is Copyright (C) 1999 SecuriTeam");
 script_family("Service detection");
 
 exit(0);
}

#
# The script code starts here
#

if(islocalhost())exit(0);
srcaddr = this_host();
dstaddr = get_host_ip();

magic_num = rand();

r1 = rand() % 255;
r2 = rand() % 255;

raw_data = raw_string(
r1,    r2,  0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x10, 0x02, 0x00, 0x00, 
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x88, 0x0D, 0x00, 0x00, 0x5C, 0x00, 0x00, 
0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x50, 0x01, 0x01, 0x00, 
0x02, 0x03, 0x00, 0x00, 0x24, 0x01, 0x01, 0x00, 0x00, 0x80, 0x01, 0x00, 0x06, 
0x80, 0x02, 0x00, 0x02, 0x80, 0x03, 0x00, 0x03, 0x80, 0x04, 0x00, 0x05, 0x80, 
0x0B, 0x00, 0x01, 0x00, 0x0C, 0x00, 0x04, 0x00, 0x01, 0x51, 0x80, 0x00, 0x00, 
0x00, 0x24, 0x02, 0x01, 0x00, 0x00, 0x80, 0x01, 0x00, 0x05, 0x80, 0x02, 0x00, 
0x01, 0x80, 0x03, 0x00, 0x03, 0x80, 0x04, 0x00, 0x02, 0x80, 0x0B, 0x00, 0x01, 
0x00, 0x0C, 0x00, 0x04, 0x00, 0x01, 0x51, 0x80, 0x00, 0x00, 0x00, 0x10);
raw_data = raw_data + "OpenPGPdetect";

IPH = 20;
UDPH = 8;
PGPNET_BASE = 137;
UDP_LEN = UDPH + PGPNET_BASE;
IP_LEN = IPH + UDP_LEN; 

ip = forge_ip_packet(ip_v : 4,
					 ip_hl : 5,
					 ip_tos : 0,
					 ip_len : IP_LEN, 
					 ip_id : 0xABBA,
					 ip_p : IPPROTO_UDP,
					 ip_ttl : 255,
					 ip_off : 0,
					 ip_src : srcaddr,
					 ip_dst : dstaddr);

dstport = 500;
srcport = 500;

udpip = forge_udp_packet(ip : ip,
						 uh_sport : srcport,    
						 uh_dport : dstport,
						 uh_ulen : UDP_LEN, #udp = 8
						 data : raw_data);
  
filter = string("((udp and dst port ", srcport, ") or (icmp)) and src host ", dstaddr, " and dst host ", srcaddr);
result_suc = send_packet(udpip, pcap_active:TRUE, pcap_filter:filter);
if (result_suc)
{
 protocol_type = get_ip_element(ip:result_suc, element:"ip_p");
 if (protocol_type == IPPROTO_UDP)
 {
  result = get_udp_element(udp:result_suc, element:"data");
  if(strlen(result) < 88) exit(0);
  if ((result[2] == raw_string(0x00)) && (result[3] == raw_string(0x00)) && 
      (result[4] == raw_string(0x00)) && (result[5] == raw_string(0x00)) && 
	  (result[6] == raw_string(0x00)) && (result[7] == raw_string(0x00)))
   {
    if (
	    (result[16] == raw_string(0x01)) && (result[17] == raw_string(0x10)) && 
        (result[18] == raw_string(0x02)))
        {
	     OpenPGP = "";
	     for (i = 0; i < 1000; i = i + 1)
	     {
	      if (result[88+i] == raw_string(0x00))
          {
           i = 1000;
          }
          else
          {
           OpenPGP = OpenPGP + result[88+i];
          }
		 }
		 if (i == 1000)
		 {
		  warning_text = "PGPNet uses OpenPGP build version: ";
		  warning_text = warning_text + OpenPGP;
          	  security_note(port:500, data:warning_text);
		 }
        }
   }
 }
}
